Whenever I read as I did again in Norman Podhoretz's article (op-ed, Aug. 27) what must be the 100th reiteration of the charge that I ruined the Democratic Party by capturing it for "the left" in 1972, I really didn't know whether to laugh or cry.

Surely Podhoretz must know that there is no ''left" of any significance or influence inside the Democratic Party. Indeed, the "left" is so small in the United States that one has difficulty finding it or identifying it. I am not applauding the absence of a political left; I simply assert what I believe is a self- evident fact.

I come from deeply Republican stock in conservative South Dakota. Only years of study as a student of history finally convinced me that the Democratic Party was by and large a little more dedicated to the average citizen's interest than the Republican Party. My half-dozen political heroes continue to this day to include such Republicans as Abraham Lincoln, George Norris and Robert La Follette. Among the Democrats, Franklin Roosevelt, Thomas Jefferson and Woodrow Wilson stand the tallest. I do not consider any of these men "leftists."

I ran for the presidency in 1972 not to capture the Democratic Party for "the left" or for any other faction. I ran to rally as many people as possible to demand that a senseless war be ended in Vietnam before it ruined our country as well as Southeast Asia. I ran in support of a fairer tax code. I ran on behalf of curbing an arms race that threatens to destroy both our fiscal integrity and our national security. I ran to replace an irrational welfare system with one that could be efficently and fairly administered through the tax code.

These are not left-wing ideas. They are down-to-earth, common-sense propositions that could lead to a happier, more secure and more prosperous nation. Some members of the press as well as some political opponents worked overtime to paint my campaign in ridiculous terms. Thus it came as a surprise to many people when, campaigning on essentially the same concepts in 1984, I appeared to be talking sense and demonstrating that after all I was a pretty level-headed fellow.

The columns of many of our major newspapers and magazines are filled these days with the writings of confused theorists such as Podhoretz, who, when not clamoring for another war are crying crocodile tears over the diminished political power of the Democrats. It is puzzling to me why they worry about this, because their views seem so close to those of the triumphant Ronald Reagan that I should think they would be rejoicing over the plight of us miserable Democrats. The government is now going forward with Star Wars, the MX and aid to the contras of Nicaragua. Aren't these all Podhoretz's priorities as much as they are Reagan's? Why is he so unhappy and fearful for the future of the republic?

What worries me is that it is the Republican Party that has been "captured" and taken to the White House by an extreme right winger. What worries me further is that the Democratic Party, which Podhoretz says I "captured" for the left wing in 1972 is so seemingly content to drift along with the Reagan policies.

If the Democratic Party or the nation is in trouble, it is not because either George McGovern or the left wing has captured it. Remember, I did not win in 1972, nor did Hubert Humphrey, Gene McCarthy or Robert Kennedy prevail in 1968, or Jimmy Carter and Ted Kennedy in 1980, or Fritz Mondale, John Glenn or Gary Hart in 1984. I don't know if Podhoretz considers these men leftists, but the point is, none of them is running either the Democratic Party or the country. The winners who captured the White House since the death of John Kennedy in 1963 are Lyndon Johnson, 1964; Richard Nixon in 1968 and 1972; Jimmy Carter in 1976; and Ronald Reagan in 1980 and 1984. These are the men who have run the country for the past quarter of a century.

All of these matters are so self-evident that I hesitate to put them in print. I do so only because I get the impression that Podhoretz somehow imagines that the Democratic Party is in the grip of the left wing and that this is causing the nation no end of grief.

He should cheer up. His team is running the country and writing most of the interpretive columns. I'm worried about all of this, but why is he?